IOWA ACADEMY OF SCIENCES. 
133 
Rumex crispus, L. 
Figure 10, plate vii. 
In this species the “palisade” cells are broader than in the 
Polygonum but not so long. The cell-cavity is short, only 
extending a short distance into cell. It is quite regular in form 
with no branching canals. The cell is light, while the cavity is 
slightly brownish. The “ sub-palisade ” cells are irregular in 
shape, being slightly oval and consisting of three layers. The 
endosperm is made up of large irregular cells about as broad as 
long. Measurements — achenium 92. 4u, “palisade ” cells 36. 3u, 
“ sub-palisade ” xiortion 23. lu. 
Rumex verticillatus, L. 
Figure Jl, plate viii. 
In this sjiecies the “x>alisade cells” are narrower and longer 
than in R. crispnis. The cell-cavity extends the whole length of 
the cell, differing in this from R. crispus, but has no projecting 
canals. The cell is light colored while the cavity is brown. The 
“ sub-x)alisade ” cells are regular in form and position. The 
endosiDerm is made up of irregular cells. Measurements — 
achenium 92. 4u, “ }3alisade ” cells 59. 4u, “ sub-]3alisade ” por- 
tion 33u. 
Rumex acetosa, L. 
Figure 12. plate viii. 
This s]3ecies has very small “jDalisade cells,” rectangular in 
shax3e and with a small cell- cavity wdiich occux^ies only a small 
portion of the lower end of the “ palisade ” cell. There are no 
canals or irregularities of the cell cavity. The cell is light 
in color while the canal is darker. The “ sub-palisade ” |Dortion 
is composed of small round cells variable in number. The 
endosperm is comx)osed of cells irregularly arranged. Meas- 
urements — whole achenium 36. 3u, “palisade cells” 23u, “sub- 
palisade” cells 13. 2u. 
Oxyria digyna, Hill. 
Figure 13, plate ix. 
In this species the “ ]Dalisade ” cells are much reduced, con- 
sisting of medium sized rectangular cells, wuth the cavity sit- 
uated in center of cell and occu]3ying the same for two-thirds 
of the distance. The cell-cavity is darker than the rest of the 
cell. The “ sub-palisade ” portion consists of two layers of 
rectangular cells, while the endosperm consists of long, regularly 
arranged cells. Measurements — whole achenium 66u, “pal- 
sade ” cells 39. 6u, “ sub-x)alisade ” 26. 4u. 
